The decomposition is $A=H+iS$. Both matrices are <Hermitian>: $H^\dagger=H$ and $S^\dagger=S$, directly from their definitions and complex conjugation of $1/(2i)$. The matrix $H$ is the <Hermitian part of a matrix>, whereas $S$ is the Hermitian matrix obtained by dividing the skew-Hermitian part by $i$.

Solution

Past exam of the mathematics course of the year 2 of the natural sciences course of the University of Cambridge / 2012 / Paper 1 / 6 / i / Solution

 Solution (source code)